Remy Melina, Lifes Little Mysteries Staff Writer | August 04, 2010 04:33am ET
The origin of man's has been a source of wonder and heated
debate for centuries.
Even Charles Darwin was unsure whether the dog's true ancestry could
be determined, because dog breeds vary so greatly. In fact, the domestic dog is far
more variable in size, shape and behavior than any other living mammal,
according to James Serpell, professor at the University of Pennsylvania
School of Veterinary Medicine and editor of "The Domestic Dog: Its
Evolution, Behaviour, and Interactions With People" (Cambridge
University Press, 1995).
There are many theories on how dogs evolved as a species, including
the view that they are mixed descendants of two or more wild species,
such as wolves, dingoes and jackals. But newer evidence hasn't supported
"Nowadays, based on a growing body of anatomical, genetic, and
behavioral evidence, most believe that the dog
originated exclusively from a single species: the gray wolf, Canis
lupus," Serpell told Life's Little Mysteries.
The similarities between wolves and dogs are great. In the 1960s,
ethologist John Paul Scott tried to untangle the behaviors of these two
species, and created a catalog of 90 behaviors of dogs. All but 19 of
them, however, were also observed in wolves, and the missing behaviors
tended to be minor activities that probably had not been recorded at the
time but do occur in wolves, Serpell said.
"Recent anatomical and molecular evidence has confirmed that wolves,
dogs and dingoes are all more closely related to each other than they
are to any other member of the family Canidae," Serpell said.
The oldest skeletal remains of probable domestic wolf-dogs were
excavated from the Upper Paleolithic site of Eliseyevichi in western
Russia, close to the Ukrainian border, and date as far back as 19,000
years. Two skulls resembled those of Siberian huskies in their general
shape, according to Serpell.
Bones of ancient domestic wolf-dogs also have been found in central
Europe, the Near East and North America, where they appear to have been
deliberately buried with their human companions or in separate graves.
The 14,000-year-old remains of a puppy and an elderly person were
found buried together in Israel, Serpell said. The person's left hand
was apparently positioned so that it rested on the dog's flank, which
shows that the relationship between man and dog is one of the oldest and
most of friendships, he said.
So what allows for dogs to get
along with humans so well?
"Several biological and behavioral factors predisposed dogs to fit
easily within human groups," said Leslie Irvine of the University of
Colorado at Boulder. "They have a long primary socialization period
during which they can become closely bonded with humans."
Dogs are active during the same hours as their owners, as opposed to
nocturnal animals, said Irvine, author of "If You Tame Me: Understanding
Our Connection With Animals" (Temple University Press, 2004). Their
loyal and obedient behavior allows them to be house-trained and to be
taught to behave in return for little more than a treat and a pat on the
In fact, a domestic dog considers its owner
or owners to be its "pack," and the owners' to be its
territory, according to "Simon & Schuster's Guide to Dogs"
"If a reciprocal understanding and affection have grown up between
man and dog, it is because the domestication of the dog took place
through an agreement on work and the division of food and lodging,"
according to "Simon & Schuster's Guide to Dogs." "This resulted in
an affectionate and intelligent cooperation and the integration of the
dog into human society."